Process for the isolation of oryzanols from crude dark acid oil (rice bran)

Abstract

A process for the isolation of oryzanols from crude dark acid oil (rice bran) which comprises (a) distilling the free fatty acids from crude dark acid oil by conventional methods, (b) hydrolyzing the resultant residue by conventional methods, (c) dissolving the hydrolyzed product in water to form oryzanol containing micellar aggregates and adding dropwise aqueous solution of calcium chloride to form precipitate, (d) extracting the oryzanols from dried precipitate with polar organic solvent and if desired (e) purifying the oryzanols from the organic extract by column chromatography.

We claim: 
     
       1. In a process for effecting production of oryzanols from crude dark acid oil as of rice bran, the improvement comprising the steps of (a) distilling the free fatty acids from the crude dark acid oil;   (b) hydrolyzing the resultant residue;   (c) dissolving the hydrolyzed product in water of amount predetermined for micellar aggregate formation in oryzanol thereby to form oryzanol containing micellar aggregates and adding dropwise aqueous solution of calcium chloride to form a precipitate;   (d) drying the precipitate; and   (e) extracting the oryzanols from the dried precipitate with polar organic solvent.   
     
     
       2. The process as claimed in claim 1, wherein the hydrolysis is carried out using aqueous sodium hydroxide solution at a temperature in the range of 60°-90° C. for a period in the range of 0.5-4 hours. 
     
     
       3. The process as claimed in claim 1, wherein the polar organic solvent used is selected from the group consisting of ethyl acetate, chloroform and methanol. 
     
     
       4. The process as claimed in claim 1, wherein the oryzanols are purified from the organic extract by column chromatography. 
     
     
       5. The process as claimed in claim 4, wherein purification of oryzanols is effected by silica gel column chromatography using polar organic eluents selected from the group consisting of chloroform, ethylacetate/hexane and chloroform/methanol.